Credit: Splash News Online

Tumultuous times for Bobbi Kristina Brown.

Despite the claims of a family source, a rep for the late Whitney Houston's family adamently denies that Brown, 19, is engaged to Nick Gordon, her "adopted" brother.

"Bobbi Kristina is NOT engaged," the rep tells us. "It is NOT true."

Still, a month after her famous mom's shocking death at age 48, Bobbi Kristina turned heads when she and Nick -- whom Houston informally adopted when he was 12 -- were photographed holding hands and kissing. Furthering the engagement speculation? The huge diamond ring on Bobbi Kristina's finger.

According to one source, the ring once belonged to "I Will Always Love You" singer Houston.

Raised like a brother and sister, Bobbi and Nick were "always close," the source says, and their relationship "has evolved a lot." These days, they are "living like a couple" in Atlanta.